1. Technical Field
The present invention relates to a liquid jet head that ejects liquid droplets onto a recording medium to perform recording, a liquid jet apparatus, and a method of manufacturing the liquid jet head.
2. Related Art
Recently, there has been used a liquid jet head of an ink jet system that ejects ink droplets onto a recording paper or the like to record characters or figures thereon, or ejects a liquid material onto the surface of an element substrate to form a functional thin film thereon. In the ink jet system, liquid such as ink or a liquid material is guided from a liquid tank into a channel through a supply path, and pressure is applied to liquid filled in the channel to thereby eject the liquid from a nozzle that communicates with the channel. When ejecting liquid, characters or figures are recorded, or a functional thin film having a predetermined shape is formed by moving the liquid jet head and a recording medium.
FIGS. 13A and 13B are cross-sectional schematic views of a liquid jet head 101 described in JP 2011-104791 A. FIG. 13A is a cross-sectional schematic view of a deep groove 105a for generating a pressure wave in liquid in the longitudinal direction thereof. FIG. 13B is a cross-sectional schematic view in a direction perpendicular to the longitudinal direction of grooves 105. The liquid jet head 101 has a laminate structure including a piezoelectric plate 104 of a piezoelectric body, a cover plate 108 which is adhered to one surface (upper surface) of the piezoelectric plate 104, a flow path member 111 which is adhered to an upper surface of the cover plate 108, and a nozzle plate 102 which is adhered to the other surface (lower surface) of the piezoelectric plate 104. Deep grooves 105a and shallow grooves 105b constituting the grooves 105 are alternately formed in parallel on the piezoelectric plate 104. Each of the deep grooves 105a penetrates the piezoelectric plate 104 from the upper surface through the lower surface thereof. Each of the shallow grooves 105b is opened on the upper surface of the piezoelectric plate 104, and the piezoelectric material is left on the lower surface thereof at positions corresponding to the positions of the shallow grooves 105b. Side walls 106a to 106c are formed between the deep grooves 105a and the shallow grooves 105b. Drive electrodes 116a and 116c are formed on side surfaces of the respective deep grooves 105a. Drive electrodes 116b and 116d are formed on side surfaces of the respective shallow grooves 105b. 
Liquid supply ports 109 and liquid discharge ports 110 are formed in the cover plate 108. Each of the liquid supply ports 109 communicates with one end of each of the deep grooves 105a, and each of the liquid discharge ports 110 communicates with the other end of each of the deep grooves 105a. A liquid supply chamber 112 and a liquid discharge chamber 113 are formed in the flow path member 111. The liquid supply chamber 112 communicates with the liquid supply ports 109, and the liquid discharge chamber 113 communicates with the liquid discharge ports 110. Nozzles 103 are formed in the nozzle plate 102, and communicate with the respective deep grooves 105a. 
The liquid jet head 101 is driven in the following manner. Liquid supplied through a supply joint 114 which is disposed on the flow path member 111 passes through the liquid supply chamber 112 and the liquid supply port 109, and is then filled into the deep groove 105a. The liquid filled into the deep groove 105a further passes through the liquid discharge port 110 and the liquid discharge chamber 113, and is then discharged to the outside through a discharge joint 115. When a potential difference is applied between the drive electrodes 116c and 116b, and between the drive electrodes 116c and 116d, thickness-shear deformation of the side walls 106b and 106c is caused. As a result, a pressure wave is generated in the deep groove 105a, and liquid droplets are thereby ejected from the nozzle 103.